Note: Descriptions are shown in the official language in which they were submitted.
- CA 022~2644 1998-10-26
W ~ 97/40245 PCT~US97/06927 --
BASE FOR INSTALLING TILED COVER~NGS AND MET~IOD FOR
USE OF SAME
FIF,T,O OF THF, ~NVl~ TION
This invention relates to the construction trades in the fields of tile and
masomy in.~t~ tions More specifically, this invention relates to the preparationof an underlying substrate for the in~t~ tion of tiled coverings.
RACKI~ROUND OF T~FI TNVF,l~TION
Many of the surfaces found in a modern building, are covered by tiled
coverings such as ceramic tiles, slate tiles, decorative glass or mirror tiles or
decorative mosaic tiles. The surfaces include floors, ceilings and walls inside the
building, as well as floors, walkways, walls, pools and other similar surfaces
outside the building. The in.~t~ tion of tiled coverings requires that the
underlying substrate be prepared to provide a smooth, level and water-
impermeable surface. The proper preparation of the underlying substrate requiressignificant skill and expertise. The current methods for preparation of the
underlying substrate is very time con~llming and laborious, increasing the time
and cost associated with such in~t~llAtions.
In recent years there has been a significant trend towards homeowners
pelroll~hlg m~intçn~nce, and even undertaking expansion projects, on their own
without employing a professional. Numerous national and regional companies
and stores cater to the owner-builders by providing products specifically
designed for non-professionals. One area of home m~int~n~nce and construction
that has largely remained the purview of professionals is the inst~ tion of tiled
coverings, particularly on vertical s~es. This is mainly due to the complexity
of the traditional methods of inst~lling tiled coverings.
In the current methods of in.~t~lling tiled coverings, a substrate must be
created to support the tiled coverings. There are two principal methods for
- creating the substrate: building up the underlying substrate or covering the
,
CA 022~2644 1998-10-26
.
WO 97/40245 PCT/US97/06927 .
underlying substrate with sheets of structural drywall.
When employing the first method, the pl epal a~ion of the substrate begins --
by creating a moisture barrier by lining the area with lightweight building paper
or similar material. Next, a combination of wire mesh, leveling sticks, and mortar
is laid down over the moisture barrier. The wire mesh is cut into strips of proper
size first and then nailed into place over the moisture barrier with special nails
that incorporate a paper spacer. The result is that the mesh is stretched taughtand spaced away from the moisture barrier. Wet mortar is then applied over the
mesh. The mortar must be leveled and uniformly distributed over the entire
surface. To assist in this process, one or more wooden strips are temporarily
fastened to the surface. These wooden strips act as reference points for leveling
the mortar to a uniform thickness. Once the mortar has been leveled, the wooden
strips must then be removed and the resulting voids filled in. The final step is to
attach the tiled coverings to the wet mortar and leveling the tiles individually to
achieve a uniform and level appeal ~nce.
The use of structural drywall is an alternative to the procedure described
above. Drywall is not as structurally sound as the method previously described,
but may be acceptable depending on the type of in.ct~ tion. Water-resistant
structural dry wall is generally available in rect~ng~ r sheets approximately 4'x8'
feet in size. To be used as a substrate for in~t~llin~ tiled coverings, structural dry
wall is first cut into strips of needed size and shape. The dry wall strips are then
fastened to the underlying substrate with fasteners such as nails or screws. Thetiled coverings are then attached to the dry wall strips. The main disadvantage of
the use of dry wall as substrate is the lack of a moisture barrier. When exposedto moisture, dry wall material will decompose and lose structural integrity,
leading to the failure of the in~t~ tion
In an attempt to reduce the susceptibility of the dry wall substrate
in~t~ tion to moisture, a concrete-type material has been substituted for the dry
wall material using the dry wall in~t~ tion method previously described. The
main disadvantages of the concrete-type material for this type of in~t~ tion are- the high weight and the brittle nature of the material. The high weight of the
-2 -
. . .
CA 022~2644 1998-10-26
W 097/40245 PCTrUS97/06921
concrete-type material makes it too heavy for certain applications such as
prefabricated housing, mobile homes or marine applications. The brittle nature of
the concrete-type material makes it difficult to cut or shape into proper-sized
strips.
The in.st~ tion oftiled coverings that are curved, or of irregular shape,
creates significant çh~llenges in the p~epalalion of a substrate. For example,
Radius tiles, tiles with a curved upper edge, are commonly used to create a
decorative border at the base of a wall. When inct~lling radius tiles, the substrate
must be built up sufficiently to accommodate the curved edge of the tile. If thesubstrate is built up too much, a gap is created between the tile and the
underlying substrate below the tile. If, the substrate is not sufficiently built up,
the tile will not "sit" properly and the inct~ tion will be uneven and llncightly
Similar challenges exist for the inct~ tion of curved or irregularly shaped tiles.
The traditional methods for preparing an underlying substrate for the
inct~ tion oftiled coverings require significant skill to execute properly. Theyare also time, and labor, intensive and lmcllit~kle for non-professionals.
The difficulty inherent in the prepa,~lion of a suitable substrate for
in.et~ tion of tiled coverings has inspired attempts at f~t~ilit~ting certain aspects
ofthe procedure. One such attempt is U.S. Pat. No. 2,852,932 issued in 1958 to
S. J. Cable. The Cable '932 patent shows a tile and grouting assembly in which aframe or lattice is provided for ret~ining ceramic tiles in place. However, the
Cable '932 assembly does not ~limin~te the need for extensive pl~,ar~tlion ofthesubstrate but merely elimin~tec the requirement for grouting between the tiles.
Another attempt in simplification of the in.ct~ tion of tiled coverings is
seen in U.S. Pat. No. 3,521,418 issued in 1970 to Bartoloni. The Bartoloni '418
patent shows a pre-finished decorative rigid panel in which tiles are set on a
fibrous backing that is il~lplegn~ed by a plastic resin to bond the tiles to thebacking support. However, while the Bartoloni '418 p~tented panel shows fixing
of the tiles in a desired pattern, it may not adequately elimin~te. the need forpl ep~ ~lion of an underlying substrate, especially if the panel is to be installed
- above a relatively flexible wooden floor and thereafter subjected to localized
CA 022~2644 1998-10-26
.
WO 97/40245 PCT/US97/06927 --
loading stresses. Also, the Bartoloni '418 p~tçnted tile panels do not include
means for interlinking adj~c~nt panels or absorbing stresses between adj~,c~nt
panels.
Another approach can be found in US Patent No. 4,551,870 issued in
1985 to Presti, Jr. The Presti '870 patent shows a modular form used as a base
for building shower stall thresholds. The form is constructed from two opposed
former sections formed of light plastic material and adapted to have mortar
poured in the space between the former sections. Tiles are ~tt~çhed to the
outside of the former section by adhering them to mortar exposed through
openings in the former sections. The approach of the Presti '870 patent is limited
to constructing shower stall thresholds and the use of pairs of opposed former
sections makes the approach uni-lit~hle for direct in~t~ tion of tiled coveringson flat surfaces. There is also no provision for ~tt~r.hin~ the former sections
directly to the underlying substrate, making the use of mortar a necessary step of
each in~t~ tiQn.
A further approach to simplifying the in~t~ tion oftiled coverings
appears in U.S. Pat. No. 5,438,809 issued in 1995 to Gernot Ehlrich. The
Ehrlich '809 patent teaches a modular flooring system consisting of units
comprised of tiles aff1xed to a backing material and surrounded by a frame.
~ c~nt units are joined together by elongate strips. This approach, however is
limited to in~t~lling tiles on horizontal surfaces, such as the floor. This approach
relies on the existence of a frame to provide additional support to the tiles and is
therefore ~ln.~llit~hle for trim tile in~t~ tions which consist of one or two rows
of tiles in.ct~lled at the intersection of a wall and the floor or the coping of a
swimming pool. Finally, the Ehlrich '809 patent does not address the in~t~ tion
of radius tiles.
Neither the traditional approaches, nor the approaches disclosed by the
patents di~cllssed above provide a general purpose product, or method, that can
be used for the in~t~ tion of tiled coverings directly on an unpr~al ed surface.Furthermore, the traditional approach of using sticks as leveling guides
- for leveling mortar applied to an underlying substrate is also time con~uming and
CA 02252644 1998-10-26
W ~ 97/40245 PCT~US97/06927 -
requires great skill to execute. The filling of voids and re-leveling of the mortar
after the sticks are removed is a difficult and skill-intensive procedure lln~llit~hle
for non-professionals.
Therefore, the need exists for a product that facilitates the preparation of
an underlying substrate for the in.~t~ tion of tiled coverings in a manner whichreduces the time, labor and expense associated with the in~t~ tion of tiled
coverings and makes it possible for the homeowners who are not professional
builders to succescfill complete tiled covering in~t~ tion projects.
A further need exists for a product that provides a permanent, embedded
leveling guide for wet mortar applied to a surface, which will elimin~te the need
for the use of temporary guides made from wooden strips.
SUMMARY OF I~IF TNVli,NTION
It is an object of this invention to provide a product that may be used as
a base for in~t~llin~ tiled coverings on an underlying substrate more easily andmore effl~.iently than existing techniques.
It is a separate object of this invention to provide, in a pl ~ ed
embodiment of this invention, a product that may be used as a base for in~t~lling
curved-edge or "radius" tiled coverings more easily and more efflciently than
existing techniques.
It is a separate object ofthis invention to provide, in a pl~fe.led
embodiment of this invention, a method for installing tiled coverings, using thebase easily and quickly.
This invention provides a way to install tiled coverings over a substrate
quickly and easily using a base that is att~ched to the substrate and upon whichthe tiles are laid.
In one embodiment of this invention a base is provided, the base having a
front and a back surface, one or more openings between the upper and lower
surfaces, one or more f~t~nine points to perrnit the att~chm~nt of the base to the
underlying substrate, and one or more spacers on the lower surface of the base.
- In a separate embodiment of this invention, the base includes one or more
, . -- ... .... . .. .
CA 022~2644 1998-10-26
.
WO 97/40245 PCT/US97/~6927 -
curved edges d~igned to cooperate with the curved edges of curved, or
"radius", tiled covering. --
In a separate embodiment of this invention, the base includes one or more
interlocking connectors on one or more edges. The interlocking connectors of
adjacent bases provide a positive connection between the a(ljacçnt bases enabling
each base to provide mutual lateral support to its adjacent counterpart thereby
increasing the lateral rigidity and stability of the overall in~t~llation
In a separate embodiment of this invention, one or more bases are
attached to the underlying substrate by m~.h~nical fasteners, such as nails,
screws or bolts. Mortar is then packed into the space between the base and the
underlying substrate and permitted to extend through the openings to the front
surface of the base. Tiled coverings are then attached to the mortar e~tçnding
through the openings by pressing the tiled covering against the upper surface ofthe base.
In a separate embodiment of this invention, the base is attached to the
underlying substrate by mechanical fasteners, and the tiled coverings are attached
to the upper surface of the base using a mastic or adhesive compound. Using thismethod, no mortar is required for the in~t~ tion of tiled covering.
It is a separate object ofthis invention to provide, in a plere,.ed
embodiment of this invention, a product that may be used as a permanently
embedded leveling guide for wet mortar being applied to a surface, which
leveling guide çliminates the need for using temporary guides during the leveling
process.
In a separate embodiment of this invention, the base includes a ledge built
on the front surface of the base to support the tiled coverings, or to provide aleveling guide for mortar.
In a separate embodiment of this invention, one or more bases
incol~ol~ling a ledge are attaçhed to the underlying substrate using meçh~nical
f~tçn~rs. Mortar is then applied to the underlying substrate and the ledge of the
base, or bases, attached to the underlying substrate is used as guide to level the
- surface of the mortar.
CA 022~2644 1998-10-26
W O 97/4024S PCTrUS97/06927
The invention and its particular features and advantages will become
more appa, enl from the following detailed description considered in conjunctionwith the accol.lpanying drawings.
RRTF,F T)F.. ~(~RTPT~ON OF T~F, I)R~W~N(',S
Figure 1 is a perspective view of the pre~l . ed embodiment for the base
illustrating the front surfacel the openings, the f~stening points and the
interlocking segmente.
Figure 2 is a perspective view of an alternative pl erel I ed embodiment of the base
additionally featuring a curved edge.
Figure 3 is a perspective view of an alternative prerelled embodiment ofthe
base? additionally featuring two curved edges.
Figure 4 is a perspective view of an alternative ple~lled embodiment ofthe
base, additionally featuring a ledge.
Figure 5 is a perspective view of the back surface of the pr~elled embodiments,
illustrating the spacers attached to the back surface of the base.
Figure 6 is a planar view of an alternative embodiment of the base, reaLul hlg an
adjustable spacer.
nF,TA~ ,n r~F~ R~pTIoN OF T~F, ll~VF,l~TI(IN
This invention provides a base for the in~t~ tion of tiled coverings on an
underlying substrate, such a wall, floor, or a ceiling inside or outside a building,
without the need for extensive plepa-alion ofthe underlying substrate. Tiled
coverings are any type of covering material that may be divided up into tiles and
installed on a surface by placing the tiles ar~jaC~nt to one another. Examples of
tiled coverings include ceramic tiles, slate tiles, natural or artificial stone tiles,
mirror tiles or decorative mosaic tiles.
The base compl;ses a backing that is generally rect~n~ r in shape and
provides the attachment point for the tiled coverings. The backing has a front
surface (~) and a back surface (2). The tiled coverings are attached to the front
surface of the backing, therefore the front surface of the backing is shaped to
... ..
CA 022~2644 1998-10-26
.
WO 97/40245 - PCT/US97/06927 - .
cooperate with the shape of the tiled coverings to be supported by the base. Flat
tiles, for example would generally be placed on a flat front surface, while curved
tiles would be best supported by a curved front surface. The back surface is
usually shaped, in conjunction with the spacers described below, to cooperate
with the underlying substrate. The backing is a portion of the base, therefore the
front surface of the backing is also the front surface of the base and the back
surface of the backing is also the back surface of the base.
The base is generally made from a material that is sufficiently rigid to
support the weight of the tiled coverings without significant distortion, yet
sufficiently light that the base may be easily transported and installed. Injection-
molded plastic is typically used for m~nllf~cturing the base, however other strong
and lightweight material, such as ceramics or composites or similar material mayalso be used.
The degree of rigidity of the base may vary based on whether mortar is
used to install the tiled coverings. In an inst~ tion where mortar is used, whenthe mortar hardens, it imparts rigidity to the base and therefore the base may be
made flexible to f~ilit~te inst~ tion If no mortar is used, the base itself must be
sufflciently rigid to support the weight of the tiled covering without subsLa,-Lial
de~"naLion. The shape of the base and the distance between the front and back
surfaces of the base may vary to cooperate with the shape, texture and weight ofthe tiled covering to be supported by the base as well as the material and contour
of the underlying substrate. The color of the material from which the base is
made may also be varied as required.
The two surfaces of the base are usually substantially parallel to one
another. There are openings (3) between the two surfaces to permit the
introduction of mortar and to reduce the weight of the base. The size of the
openings should be large enough to perrnit easy introduction of mortar and smallenough to retain the mortar packed between the back surface of the base and
underlying substrate. The size of the opening, or openings, is also limited by their
effect on the structural integrity of the base. The size and shape of the openings
may be either uniform or varied.
-8 -
CA 022~2644 1998-10-26
W 097/40245 PCT~US97/06927 -
One or more of the openings between the front and back surfaces of the
base may be used as f~.ctening points (4). Mechanical type fasteners such as nails,
screws or bolts (10) may engage the underlying substrate through the f~ctçning
point and attach the base to the underlying substrate. The f~stening points may
be of the same shape and size as the openings between the front and back
surfaces of the base, or they may be of a di~~ l size and shape. For economy
of design and construction, the base may be m~n~lf~ctllred such that subst~nti~lly
all openings between the front and back surface of the base may be used as
f~teninE points.
The f~tening points may be placed at intervals that correspond to the
intervals of structural features in the underlying substrate which can support the
base and the tiled coverings. Such features include studs and load bearing
columns, and the interval between such features is generally ree~ ted by local
building codes or state or national regulations. The interval between the
f~tening points on the base, between ~ cent bases, is keyed to the applicable
codes and regulations re~ ting the pl~cement of the structural features
described above.
The spacers (8) are part of the back surface, projecting out from the back
surface in the direction of the underlying substrate. When the base is attached to
the underlying substrate the spacers contact the underlying substrate and
m~int~in a gap between the back surface of the base and the underlying
substrate. Generally, the spacers are uniform is size and distribution, althoughboth the size and distribution of the spacers may be varied to permit the base to
cooperate with the underlying substrate to align the upper surface of the base
with the desired plane for the inst~ tion of the tiled coverings.
As shown in figure 6, the spacers may also consist of mef~.h~nic~l
f~etençrs such as nails or screws ~ttached to the underlying substrate and each
having a top which supports the back surface of the base (9). The top of the
me~.h~ical fasteners forming the spacers in this embodiment may be sufficiently
exposed through an opening in the base to permit the di~t~nce between the base
and the underlying substrate to be adjusted during and after in.ct~ tion such that
.. . . . . . . . . .
CA 022~2644 1998-10-26
WO 97/40245 PCT/US97/06927 -
the front surface of the base may be placed in a desired plane irrespective of the
contour of the underlying substrate.
During inst~ tion, the base is ~tt~h~d to the underlying substrate
through ~tt~r.hmP.nt points built into the base. In one prerelled embodiment,
mortar may be introduced into the space between the base and the underlying
substrate and the tiled coverings may be attached to the mortar presented at theopenings on the base. The mortar fills the gap between the base and the
underlying substrate and att~ches to the tiled covering placed on the base. The
mortar comes into contact with the tiled covering through the openings in the
base. When the mortar hardens it creates a firm bond between the underlying
substrate, the base and the tiled coverings. Although the use of mortar is not
required in all in~t~ tions, it may be emp}oyed when deemed advantageous.
In an alternative embodiment, after the base is attached to the underlying
substrate, the tiled coverings may be attached to the base using a mastic or
adhesive and the in.ct~ tion accomplished without mortar.
The tiled coverings adhere to the mortar that fills the space between the
base and the underlying substrate and which is presented through the openings inthe base. Alternatively a mastic can be used to adhere the tiled coverings directly
to the front surface of the base, thus el;~ g the need for mortar. Generally,
however, any bonding agent, such as mastic, adhesive or mortar may be used to
attach tiled coverings to the front surface of the base.
Bases can be placed adja.cent to one another to cover a large surface. The
bases can be m~mlf~ctllred in di~rerellL shapes and sizes to accommodate varioustypes of in~t~ tions. The bases may be made from material of di~lt;..l color to
match the tiled covering or mortar that is used in the in~tall~tion
The front surface of the base provides a clean surface, shaped to
cooperate with the shape of the tiled coverings used. Flat tiles, for example
would typically use a flat base for inst~ tion, while curved tiles would best besupported by a curved base.
The use of a base att~çhed to the underlying substrate using mech~nical
- fasteners ~li.. ~in~tes the time con~ lming prepal~Lion ofthe underlying substrate
-10-
.. .. . . .
CA 022~2644 1998-10-26
W ~ 97/40245 PCTrUS97/06927 --
required by the earlier methods. It permits relatively inexperienced individuals to
install tiled coverings perfectly. In some in~t~ tions, it elimin~tes the need to
apply mortar to the surface. The ~limin~tion of mortar leads to a lighter, faster,
easier and consequently more inexpensive in~t~ tion.
Certain tiled coverings have a curved or 'radius' edge or edges. For
example, the tiles used to create a decorative border at the base of a wall have a
curved upper edge. For the proper in~t~ tion of radius tiles, both the flat bodyand the curved edge, or edges, of the tile must be ~(lequ~tçly supported by the
underlying substrate, or the base of this invention.
One embodiment of the base would include one or more curved edges
desi~ed to cooperate with the curved edge or edges of a radius tile. The
curvature of a single edge makes this embodiment of the base, when viewed
from the side, resemble the body of the letter "j". The curved edge may be
m~nllf~ctured to be integral to this embodiment of the base, or it can be
m~nl-f~ctl-red as a separate section having the desired curvature that is attached
to a base prior to, or during in~t~ tion The separate curved edge may also be
installed separately on the underlying substrate without being attached to a base.
When the curved edge or edges are m~n-lf~ctl~red as integral parts of the base, a
weakened section may be provided to f~.ilit~te the separation of the curved edgefrom the base, if desired.
This alternative embodiment of this invention, (figures 2 and 3) provides
a base having one or more curved edges (6) to support the curved edges of
radius tiled covering. The curvature of the curved edge, or edges, is designed to
cooperate with the curved edge or edges of the tiled coverings installed on the
base. Different curvatures are possible depending on the requirements of the tiled
coverings being installed. Each curved edge of the alternative embodiment
provides support for the corresponding curved edge of the tiled covering. The
use of this embodiment ç~ es the need to build up the underlying substrate
to COI~llll to the shape of the radius tiled covering, which is a far more complex
and error-prone task than the preparation of the substrate for the in~t~ tion of- flat tiled coverings.
CA 022~2644 1998-10-26
..
WO 97t40245 PCTIUS97/06927
When a base of this invention includes a radius edge, all the advantages
of the principal invention can benefit the in~t~ tion of curved or radius-edged
tiled coverings. The use of the base with a radius edge ~limin~tes the need to
prepare and build up the underlying substrate for the specific shape of the radius-
edged tiled coverings. The use of this alternative embodiment permits in~t~ tionof radius tiled coverings by relatively inexperienced individuals and achieving
results hitherto obtained by experienced professionals only. The use of this
alternative embodiment by a professional can significantly reduce the time and
expense associated with the in~ tion of radius tiled coverings.
An alternative embodiment ofthis invention incllldes a ledge (figure 4).
The ledge (7) is part of the front surface of the base that is built up to a selected
distance from the front surface. The ledge is generally built up to a right angle
from the front surface of the base, although any other angle may be selected if
desired. The ledge serves two discrete functions: it may be used to cooperate
with the bottom edge oftiles ~tt~çhed to the base, or it may be used as a guide
for leveling mortar. The ledge is generally made from the same material as the
base itself, but if needed, it can be made from a dirrel enl material to achieve a
di~renl degree of rigidity, di~re.ll color or other unique properties required by
the particular tiled covering or in~t~ tion.
The use of a ledge to support the bottom edge of tiled coverings provides
for a more convenient in~t~ tion When the tiled covering is attached to the
base in substantially vertical orientation, the tiles are pr~ bly supported while
the mortar, or mastic, is drying. If the consistency of the mortar is not precisely
controlled during the traditional in~t~ tion techniques, the tiled coverings maysirnply fall offthe wall before the mortar is dry. A support ledge prevents the
tiled coverings from falling and gives the mortar or mastic a chance to adhere to
the tiled coverings. In effect, the use of the base with the ledge makes the
in~ts~ tion process more forgiving to errors, thus making it possible for
individuals with relatively little experience to achieve professional-like results.
The p,~relled embodiment featuring a ledge may also be used as a
leveling guide for wet mortar. In this application, the base is ~1t~ched to the
-12-
CA 022~2644 1998-10-26
WO 97/40245 PCT~US97tO6927
underlying substrate with meçh~nical fasteners such as nails, bolts or screws with
the back surface facing the underlying substrate. The mortar is then applied to
the underlying substrate, such as a wall or floor in sufficient depth to cover the
base and the ledge. The tip of the narrow edge of the ledge can then be used as a
S guide to level the mortar using a straight edge, 2-by-4 plank or other suitable
tool.
An alternative embodiment of the base includes interlocking segmentc
along the edge of the base that permit each base to be securely connected to oneor more adjacent bases. The typical interlocking mech~ni~m is a tongue and
groove connector, although other types of interlocking mec.h~nism.~ may also be
used. The interconnection of ~dj~cent bases creates a more rigid overall surfacefor the inct~ tion of tiled coverings. The base of this invention may be
m~n~f~ctured in standard sizes and shapes. Preferably, the interlocking segm~ntsare standardized and would permit bases of di~el ent shapes and sizes to be
attached to one another. The ability to attach adjacent bases of same or di~e,en~
shapes and sizes together allows great variety in the size, shape and contour ofthe area to be covered by tiled coverings. The use of interlocking segments
preserves sufflcient flexibility in the overall base surface to accommodate the
normal flexing of the underlying substrate and the tiled covering while providing
enhanced overall rigidity to the in~t~ tinn.
The features of various alternative embodiments of this invention may be
co",billed in numerous variations to create bases for particular installations and
requilenlcllls For example~ one such co-"bh~alion may consist of a base with
curved upper edge and a ledge but no interlocking segm~nt~ Other variations
are also possible co"lbh~ing the features described to form specific base
configurations.
~Although the invention has been described with reference to a particular
all ~nge~ent of parts, features, steps and the like, these are not int~nded to
exhaust all possible arrangements or features. Many other modifications and
variations will be ascertainable to those skilled in the art.
